LRP6 and pulmonary fibrosis: These results confirm that exercise improves the progression of pulmonary fibrosis at the histopathological level, and previous studies illustrated that it may be partly related to the promotion of attenuation of 5-hydroxytryptamine/protein kinase B (5-HT/Akt) (46) and the suppression of Transforming growth factor beta 1 (TGF-β1) / Smad proteins and Low-density lipoprotein receptor-related protein 6 (LRP-6)/β-catenin signaling pathways (47).